The present invention relates to methods and apparatus for customizing and testing meters and more particularly relates to the customization and testing of fully assembled electronic postage meters which operate under control of resident operating programs and include nonvolatile memories (NVMs), of the type such as disclosed in the aforementioned related patent application.
Known electronic postage meters employing firmware such as disclosed in U.S. Pat. No. 4,301,507, issued on Nov. 17, 1981, and assigned to Pitney Bowes, Inc. of Stamford, Connecticut, are programmed via (Programmable) Read Only Memory (PROMs) to undergo a certain sequence of operations. In dealing with a single postal system such as that in the United States, one setof software is programmed into the meter. However, when an electronic postage meter is used with a number of different postal systems, i.e., internationally, where the requirements of the postal systems of various countries vary widely, a number of different individual programs or software packages are required to accommodate the variations between the individual countries. Such a multiplicity of software packages greatly increases the cost of the meter.
In addition, prior art techniques for manufacturing meters for use in one of a multiplicity of countries are typical component oriented. According to these manufacturing techniques, NVMs are initialized and configured to produce country dependent NVM components. These components were subsequently handled by operators to fabricate meters for a given country in a batch type assembly operation. The data base installed in each NVM was designed to work with one of the aforesaid multiplicity of software packages in a meter's (P)ROM.
In order to increase the inherent reliability of meters by reducing the handling of components, it has proven to be desirable to be able to customize fully assembled meters.
Copending application Ser. No. 447,925, filed on Dec. 8, 1982, entitled, CONTROLLING FIRMWARE BRANCH POINTS IN AN ELECTRONIC POSTAGE METER, now U.S. Pat. No. 4,636,975, which a discloses one way in which a number of individually tailored software packages and user handling of components may be reduced by setting certain data bits in nonvolatile memory (NVM) of a fully assembled meter to control firmware branch points. Further, copending application Ser. No. 729,395, filed May 1, 1985, entitled MODIFYING A FIRMWARE VARIABLE IN AN ELECTRONIC POSTAGE METER, discloses another technique for reducing the number of individually tailored software packages and user handling of components by setting certain data bits in NVM of a fully assembled meter to modify a firmware variable in ROM.
The methods disclosed in both these copending applications are directed at modifying selected portions of programs or data sets stored in a postage meter, prior to shipment, to configure a meter for a chosen country. Both applications, for security reasons, call for locking out attempts to reconfigure a meter after the meter serial number is placed in memory.
Yet another method and apparatus for customizing a fully assemble meter is set forth in U.S. Pat. No. 4,528,644 to Soderberg,et al, entitled CUSTOMIZING THE FIRMWARE AFTER THE ASSEMBLY OF AN ELECTRONIC POSTAGE METER, assigned to the same assignee as the current invention.
The objects of the invention disclosed in U.S. Pat. No. 4,528,644 were to provide a customized electronic postage meter in which program variations are minimized; to provide customization of an electronic postage meter after final assembly (achieving the aforementioned increased inherent reliability); to provide an electronic postage meter which is capable of employing generalized firmware for use with different postal systems; and to provide a firmware controlled international electronic postage meter in which programming costs are minimized.
U.S. Pat. No. 4,528,644 teaches customizing a fully assembled meter by storing a configuration program within the electronic postage meter which program is capable of configuring the meter in response to configuration input messages, inputting configuration messages into the electronic postage meter to select the desired meter functions and provide data for use with operating programs stored in the meter, storing the configuration input data in the assembled meter under control of the meter configuration program for subsequent interaction with the operating programs of the meter to provide predetermined meter functions, and denying further access to the configuration program prior to placing the meter in service.
The prior art, although enhancing meter reliability by providing for the customization of fully assembled meters, again may be seen to inherently prevent the reconfiguring of a meter. Security considerations dictated the need for the aforementioned prohibition on reconfiguration. In fact, postage meters have traditionally been fabricated in such a manner as to render further use virtually impossible if reconfiguration or disassembly was attempted by the operator. Current manufacturing techniques call for NVMs and postage meter Random Access Memory (RAM) to be soldered in place. This in effect dictates that memories can not be interchanged, replaced or swapped without disassembly at the component level. This can lead to damage of sensitive meter components and in the case of testing, the loss or destruction of failure data.
The traditional approach to providing meter security, in part by not allowing certain meter parameters to be changed and not permitting the reconfiguration of a meter after final assembly, has given way to the desire to be able to have the flexibility to perform reconfiguration post assembly while maintaining security. This would enable a given meter to be operated in one country and then allow it to be reconfigured for use in another country.
An electronic postage meter which permits post assembly access by authorized personnel to various defined meter security levels (and particular parameters) is set forth in copending application Ser. No. 823,901, patent pending, incorporated herein and cross-referenced hereinbefore.
In addition, as far as security is concerned, it should be understood that prior art methods for manufacturing and initializing a meter typically involve interaction between the meter, an operator and a data center to correlate a meter's serial number with an encrypted meter ID called a "seed", stored in both the meter and at the data center. Besides being used to uniquely identify a meter, the seed is used to specify and keep track of sensitive meter data such as the amount of postage the meter is authorized to print.
The prior art methods for "seeding" sealed meters requires the operator to handle magnetic tapes or other hard copies of these highly sensitive seed values.
Finally, the prior art also requires the use of storage within the meter itself to store configuration programs, thereby requiring such programs to be maintained and take up storage that could be utilized for other purposes.
It is the need to maintain overall security in programmable electronic postage meters; to be able to initialize, configure, and reconfigure meters post assembly; to be able to handle sensitive meter data in a manner transparent to the user; to be able to perform nondestructive testing and to be able to maximize the use of a meter's resources (e.g. program store), that sets the backdrop for the invention described hereinafter.